A magnetometer is an instrument used to measure the strength and/or direction of the magnetic field in the vicinity of the instrument. Many electronic devices exist that utilize a magnetometer for taking measurements for a particular application, e.g. geophysical instruments, aerospace equipment, and mobile communications devices such as cellular telephones, PDAs, smart phones, tablet computers, etc., to name a few.
Mobile communication devices, such as those listed above, may only be interested in the Earth's magnetic field. For example, a compass application on a mobile communication device may only be interested in the direction of the Earth's magnetic field.
A mobile communication device typically operates in various different locations and under various circumstances. Changes in the environment in which the mobile communication device operates can affect the operation of the magnetometer. Furthermore, magnetic interference from the environment and/or components of the mobile communication device itself, can cause a magnetometer reading to deviate from the Earth's magnetic field. As such, the magnetometer reading of the mobile communication device may not accurately indicate the Earth's magnetic field.